The buzz of angry bees could provide some relief for African villagers whose crop fields are regularly pillaged by hungry elephants.

Oxford University researchers found that elephants would quickly vacate a spot after hearing recordings of bees.

The insects are able to inflict painful stings inside the animals' trunks, and it is thought that elephants have learned to avoid them.

The research is reported in the scientific journal Current Biology.

"We're a bit cautious about how effective this would be on a large scale," lead researcher Lucy King told the BBC News website from Kenya, where she is running field trials.

"But bees may become one deterrent that farmers could use in the right situation."

Elephants are partial to maize, the principal crop for millions of Africans. Typically the animals seek out the crops just before harvest time.

On the run

The Oxford team set up concealed loudspeakers in trees where elephants regularly came to find shade.

Elephants are smart and would work out that there are no painful beestings

Lucy King

While the animals rested, researchers played either buzzing sounds recorded at beehives, or a control sound of white noise.

The buzzing clearly had the animals concerned. Ninety-four percent of the elephant families left the tree within 80 seconds of hearing bee sounds, nearly half of the time at a run.

White noise, by contrast, only scared away 27% of the families.

"So you could use sounds to deter elephants," noted Dr King, "but there are two major hiccups.

"Firstly, farmers don't have money to pay for a loudspeaker and a minidisc, and on that level it's not practical. Secondly, elephants are smart and would work out that there are no painful beestings; we don't know if that would happen after three playbacks or 30, but it is clearly going to happen."

It might be more practical and more desirable, she believes, to use real bees rather than their sounds.

De-fence

Another of the projects that the group is running in Kenya involves creating a "beehive fence", where the passage of a hungry elephant would trigger bees to start flying and buzzing, giving the animal cause to turn and not come back.

Elephant families would respond to the buzzing, often leaving quickly

One experimental set-up involves suspending a chain of hives from stanchions, linked together by wires which would be disturbed by an elephant's leg.

In certain situations, putting more bees into rural communities could help crop yields and provide honey either for local consumption or sale.

But African bees are quite aggressive and cause painful stings, so some communities might not welcome them.

Lucy King has felt their dark side more than once, having had a swarm settle on her during field trials.

"I was just covered in the things, and they are very scary, very aggressive," she recalled.

"They sting you and they die; and when they sting you it releases a pheromone that encourages others to sting you. I was stung once on the jugular vein, so I've been very lucky."

The research was partly funded by the organisation Save the Elephants, which has as part of its mission "to develop a tolerant relationship between the two species" of human and African elephant.